For most people, I don't think there's much incentive to push 1440p/4K. Namely, prices are high. Not everybody's going to invest in more expensive CPU's, GPU's, or whatever.
Sure, I have a 4K monitor - but I bought that b/c at that time b/c I really wanted a 1440p monitor at that time. Saw a Samsung 4K for similar prices on sale - just decided to go with that instead. Just gotta pump up AA to the moon, to stop any sort of blur or anything at 1440p. Two birds, one stone here, as I can run 1440p on everything pretty much - and I'm all set here for the inevitable 4K future.
Oh, BTW - that SC15 laptop from EVGA came back in on sale the other day at $1000 and I jumped on it. Good thing I did, b/c now it's back at $1900. Can't wait for this to, more or less, replace my current gaming laptop: Acer Nitro V15 Nitro (VN7-591G-79YZ).
EDIT:
why dont you do what mysterd does and use a low end video card to run at 4k so you can have more desktop space
970 is not low-end. It's one of the higher ends of the 9xx series.
What's above it (in that series)? Maybe the 970 Ti, 980, 980 Ti, and Pascal's Maxwell's Titan?
Aging might be a better word choice for it, as the 10xx series is out and that the 11xx series is right around the corner.
I run most stuff here at 1440p at Medium-to-High at 30fps to 60fps (depends per game - I often find somewhere I'm fine with in-between to lock it down via NVidia Inspector or MSI AB), which was my intent anyways. If I can run 4K with some games (such as older titles at that resolution and WWE 2K series & MK series) - cool, but it really just ain't expected here for me to do 4K on everything just yet.
4K everything seems to be in the 1080 Ti range.